Can't really compare the two games like you can compare Torchlight to Diablo.
I personally really like the skill system for Path of Exile and the darker tone that actually evokes a better feel of DIablo II than Diablo III did. The possibilities of builds in Path of Exile are endless with their skill system, it's quite great.
I love Torchlight, but I'm going to have to say Path of Exile for long term enjoyment. It is an MMO after all. And Grinding Gears is planning to add new contents/Acts consistently
i believe PoE has the original diablo feel, with a lot more freedom then this game has, but as a more casual friendly, and easily moddable game, torchlight 2 is superior, its just a choice of what you want to do.